Assessment of in vitro alpha-glucosidase inhibitory activity, phenolics, flavonoidsand antioxidant potential of jamun (Syzygium cumini) seeds

Jamun (Syzygium cumini Linn. Syn. Eugenia jambolana) genotypes collected from different parts of the country were evaluated for in vitro alpha-glucosidase inhibitory activity, polyphenolic content and antioxidant potential along with fruit characters. Results indicated significant variation among genotypes for fruit characters, phenolics, flavonoids, antioxidant potential, and alpha-glucosidase inhibitory potential. Total phenolics and flavonoids in seeds varied between 15.5 mg to 98.7 mg GAE/g and 0.79 mg to 9.03 mg CE/g seeds, respectively. The seeds with a high content of polyphenolic compounds required a very less amount of sample to inhibit alpha-glucosidase enzyme. The genotype Selection 45 recorded the highest alpha-glucosidase inhibitory activity, and required only 50.3 µg of sample to inhibit 50 % of the enzyme activity. Both phenolics and flavonoids content positively correlated with antioxidant potential and negatively correlated with enzyme inhibitory potential. From cluster analysis, the genotypes AJG-85, Kaithanal, Selection-45, Collection-2, and Konkan Bahdoli were identified as superior genotypes having a considerable amount of seeds with alpha glucosidase inhibitory compounds. These genotypes/collections may be effectively utilized for further studies to isolate and characterize the bioactive constituents with alpha-glucosidase inhibitory potential.